I grew up a child of the 90s, not really the Grunge movement but the stuff that came out of it. So stuff like Foo Fighters, Tool and Perfect Circle, Soundgarden, Bush, Smashing Pumpkins, Alice in Chains, Silverchair, Sponge, Bad Religion, Deftones, they always find their way to my playlists. The more recent stuff I listen to tends to follow that path too: Rise Against, Anberlin, 32 Leaves, Red, Skillet, Breaking Benjamin, Disturbed, Three Days Grace, Chevelle. Pandora serves me up quite a bit at work, and I'll usually give an artist at least a listen.

But I also was raised with a lot of classic rock around, and I find myself sticking with some of the real creative forces there. Obvious stuff like Led Zeppelin and Pink Floyd, sure, but also King Crimson, Rush (2112 > Moving Pictures), Kansas, The Clash, Depeche Mode, they aren't going anywhere either.

To say nothing of my love of vidja gaem musik. A shout out to my boy SupraDarky, who's been picking the best game music for nearly a decade now for playlists and whose lists I tend to have running in the background whenever I'm playing an MMO or otherwise doing something where the audio isn't too important. Highlights of my recent listens include the obligatory Chrono Cross mention, the realization that Umineko's soundtrack is way more awesome than you would expect from a Visual Novel, and the reminder that Neir was seriously underrated as a game and soundtrack.

I recently picked up a few songs by 'Jay Ungar & Molly Mason'. All instrumentals with a rather sad tone. I've always been rather partial to sad tunes.
Great background music that doesn't distract you while you work on things, or just need to mellow out.

"Hao! Dai ye! We won again! This is good, but what is best in life?"
"The open steppe, fleet horse, falcons at your wrist, and the wind in your hair."
"Wrong! Conan! What is best in life?"
"Crush your enemies. See them driven before you. Hear the lamentations of their women."

I just got turned on to The Record Company. Another favorite is Grace Potter. Basically any good rock or blues rock. Where I live there's only one radio station that really plays new stuff so I have to hunt for new things through other means.